List two general reasons why scientists are likely to collaborate

Two scientists may try to collaborate under Few circumstances :-

Every scientist have their II level of knowledge and creativity on combining two it might result in a better outcome Mistakes of one can be analysed and covered by the other thereby increasing the chances of getting good results.

A rather greatest spectrum of knowledge  would be present as the knowledge of two scientists would always be more than one Which is also true in the case of expertise in more than one subject can be there.  

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.